Isuzu KB P190. Manual - part 70

POWER-ASSISTED STEERING SYSTEM 3B-19 

Disassembly 

1.  Clean the oil pump with solvent (plug the discharge

and suction ports to prevent the entry of solvent). 
Be careful not to expose the oil seal of shaft 
assembly to solvent. 

2.  Remove the bolt, suction pipe and O-ring. 
3.  Remove the connector, O-ring, relief valve and

spring. 

4.  Remove the bolt, rear housing and O-ring. 
5.  Remove the snap ring. 
6.  Remove the shaft assembly. 
7.  Remove the oil seal. 

CAUTION: When removing the oil seal, be careful
not to damage the housing. 

8.  Remove the pump cartridge assembly from the front

housing. 

9.  Remove two O-rings. 
 

Inspection and Repair 

Make all necessary adjustments, repairs, and part
replacements if wear, damage, or other problems are 
discovered during inspection. 
 

Rotor 

442RS002

Check that the groove in the vane is free from excessive
wear and that the vane slides smoothly. When part
replacement becomes necessary, the pump cartridge
should be replaced as a subassembly. 
 
 
 

 

Vane 

442RS003

Sliding faces of the vane should be free from wear.
(Particularly the curved face at the tip that contact with
the cam should be free from wear and distortion). When
part replacement becomes necessary, the pump
cartridge should be replaced as a subassembly. 
 

Cam 

The inner face of the cam should have a uniform 
contact pattern without a sign of step wear. When part
replacement becomes necessary, the pump cartridge
should be replaced as a subassembly. 
 

Side Plate 

The sliding faces of parts must be free from step wear 
(more than 0.01 mm (0.0004 in)), which can be felt by 
the finger nail. 
The parts with minor scores may be reused after lapping
the face. 
 

Relief Valve 

The sliding face of the valve must be free from burrs
and damage. The parts with minor scores may be 
reused after smoothing with emery cloth (#800 or finer).
 

Shaft 

Oil seal sliding faces must be free from a step wear
which can be felt by the finger nail. Bushing fitting face
must be free from damage and wear. 
 

O-ring, Oil Seal, Snap Ring 

Be sure to discard used parts, and always use new
parts for installation. Prior to installation, lubricate all
seals and rings with power steering fluid. 
 

3B-20 POWER-ASSISTED STEERING SYSTEM 

Reassembly 

1.  Install oil seal to front housing. Be sure to discard

used oil seal, and always use new parts for 
installation. 

CAUTION: When installing the oil seal, be careful
not to damage the oil seal contacting surface of the
housing. 

2.  Install shaft assembly. 
3.  Install the vanes to roter with curved face in contact

with the inner wall of cam. 

442RS005

 

4.  Install roter and vanes to cam. 
5.  Install pin to front housing. 
6.  Install two new O-rings to front housing. Be sure to 

discard used O-ring. 

7.  Install side plate. 

CAUTION: When installing side plate, be careful not
to damage its inner surface. Damaged side plate
may cause poor pump performance, pump seizure 
or oil leakage. 

8.  Install pump cartridge assembly to front housing. 
9.  Install snap ring to shaft end. 
10. Install rear housing with a new O-ring. Be sure to 

discard used O-ring. Then install bolt and tighten it 
to specified torque. 

Torque: 25 N･

･･

･m (2.5 kgf････m/18 lb････ft) 

11. Install suction pipe with a new O-ring. Be sure to 

discard used O-ring. Then install bolt and tighten it 
to specified torque. 

Torque: 10 N･

･･

･m (1.0 kgf････m/87 lb････in) 

12.  Install relief valve and spring. 
13. Install connector with a new O-ring. Be sure to 

discard used O-ring. Tighten the connector to 
specified torque. 

Torque: 59 N･

･･

･m (6.0 kgf････m/43 lb････ft) 

 

Main Data and Specifications 

General Specifications 

Oil pump 

Type 

Vane 

 Operating 

fluid 

ATF DEXRON

®

―III 

 

POWER-ASSISTED STEERING SYSTEM 3B-21 

Torque Specifications 

4JH1-TC, 4JA1-T 

N･m (kgf･m/Ib･ft) 

 

 

 

RTW73BLF000901 

3B-22 POWER-ASSISTED STEERING SYSTEM 

Power Steering Pump (4JJ1-TC, 4JK1-TC) 

Power Steering Pump and Associated Parts 

  

 

RTW53BMF000201 

Legend 

(1) Pump Assembly 

(2) Flexible Hose 

 

 

(3) Bolt 

(4) Suction Hose 

(5) Nut 

 

 

Removal 

1.  Remove the cooler compressor drive belt. 

2.  Place a drain pan below the pump. 

3.  Disconnect the suction hose. 

4.  Disconnect the flexible hose. 

5.  Remove the power steering fixing nut, and remove

the pump assembly. 

 

Installation 

1.  Install the pump assembly. Tighten the fixing nut to 

the specified torque. 

 Torque: 

 25 N·m (2.5 kgf·m/18 lb·ft) 

 

2.  Install the flexible hose. 

 

Tighten the bolts to the specified torque. 

 

Torque: 8 N·m (0.8 kgf·m/69 lb·in) 

3.  Install the cooler compressor drive belt. 

4.  Connect the suction hose, then fill the power steering 

fluid and bleed the power steering system. 

 

Refer to Bleeding the Power Steering System in this 

section.